(70) باب صَوْمِ النَّبِيِّ صلى الله عليه وسلم - بِأَبِي هُوَ وَأُمِّي - وَذِكْرِ اخْتِلاَفِ النَّاقِلِينَ لِلْخَبَرِ فِي ذَلِكَ
It was narrated that Hafsah said:
"The Messenger of Allah used to fast Thursday and Monday of each month, and Monday of the following week." (ID)
Reference (ID): Sunan an-Nasa'i 2366 (ID)
In-book reference (ID): Book 22, Hadith 277 (ID)
English translation (ID): Vol. 3, Book 22, Hadith 2368 (ID)